How to power on the gauge cluster with engine off.

GP1200R 01. Actually this is a question rather than a how to. Does anyone know how to test the display with the engine off? I assume you need to remove the cluster and connect to a battery (which wires?) to do it. I'm trying to read the hours but my engine is apart at the moment.

I can't exactly make out the numbers as there is a bit of water clogged between the plastic and the LCD itself. Is there any point trying to rescue this unit? I know some of the Polaris guys were able to bring poor lcd units back to life just wondering if anyone attempted something similar